#include<bits/stdc++.h>//太难了看不懂的代码
using namespace std;
int main(){
int n,i,j;
cin>>n>>i>>j;
int d=min(min(i-1,n-i),min(j-1,n-j));
int idx=d+1,jdx=d,k=4*(n-d)*d;
int minidx=d+1,maxidx=n-d,minjdx=d+1,maxjdx=n-d;
while(idx!=i||jdx!=j){
while(jdx+1<=maxjdx){
jdx++;
k++;
if(idx==i&&jdx==j){
cout<<k;
return 0;
}
}
minidx++;
while(idx+1<=maxidx){
idx++;
k++;
if(idx==i&&jdx==j){
cout<<k;
return 0;
}
}
maxjdx--;
while(jdx-1>=minjdx){
jdx--;
k++;
if(idx==i&&jdx==j){
cout<<k;
return 0;
}
}
maxidx--;
while(idx-1>=minidx){
idx--;
k++;
if(idx==i&&jdx==j){
cout<<k;
return 0;
}
}
minjdx++;
}
}